Ah, language! So many levels!

General: universal, genera
Specific: particular, species

Actually the title of this thread is misleading from the outset. To say that a universal is a 'thing' is the exact definition of reification or hypostatisation:

hypostatisation - regarding something abstract as a material thing
hypostatization, reification
objectification - the act of representing an abstraction as a physical thing

You can say that universals are real but that they are not 'existing things'. If that basic distinction can be accepted, many of the issues will be resolved.

@aletheist - I believe this is similar to a point repeatedly made by Peirce with respect to the difference between what exists and what is real.

I believe this is similar to a point repeatedly made by Peirce with respect to the difference between what exists and what is real. — Wayfarer

Yes, and @Terrapin Station is aware that I make the same distinction. That is why we switched to <<whatever>> in the course of the exchange, to avoid implying any commitments either way regarding existence vs. reality vs. being etc. We also stumbled over his initial use of "separate" to describe the relation between potential and actual points on a truly continuous line. In other words, it is proving difficult to come up with neutral terminology, rather than expressing things in ways that inherently reflect our different positions.

In other words, it is proving difficult to come up with neutral terminology. — aletheist

That is to be expected in a world where only particulars exist. Really it ought to be clear that it makes discussion pointless.

Really it ought to be clear that it makes discussion pointless. — Wayfarer

Just to be clear - what makes discussion pointless?

There are two things that Terrapin Station claims: meaning is subjective, and only particulars are real. I think the implication of that is: discussion is pointless, because you can never be clear that you're comparing like with like, and so, what the other party means by anything he or she says. And that is indeed borne out by the last several pages of this debate, wouldn't you think? It seems (at least to me) to have been going around in circles.

Maybe, but I appreciate the dialogue as an opportunity to sort out my own approach to these matters. As the saying goes, "I write to find out what I think."

You could never be sure you were not comparing like with like either.

Right. So if you were asked 'what does 2 + 2 equal', would you answer, 'depends on what you mean by "2" '?

I would answer 4?

How could you be sure you were adding 'like' to 'like'?

How would I be sure I was not?

Look - what is at issue in all of this discussion is the reality, or otherwise, as such basic concepts as the law of identity, and the like. Realists - scholastic realists, not today's 'scientific realists' - say that such things as logical laws and concepts and the like are real; and that these are basically similar in kind to other universals. They're not just real because of social convention, or because people agree that they're real; they're real independent of social consensus or convention.

But at the same time, they're 'mental objects' i.e. they can only be grasped by a rational mind, they don't exist in the way that particular objects exist. And this the stumbling block for physicalists: there is only one 'way' anything can exist, and that is, as a material object or physical force. As soon as you admit that abstract 'objects' (and as noted, they're not actually objects) are real, it's game over for materialism.

I fail to see the issue here?

Why can't mental objects be real, or physical?

Only to the eliminativists who equate existence with real. Non-eliminative materialists have no such issues.

Where logic is recognised as real in the first instance, as opposed to the illusionary and finite presence of an existing state (dependence on an existing object or mind), existence isn't required for logical laws and expression to be true. Logic or universals are true without existing. The mental/physical of substance dualism is a red-herring.

Logic's independence is given by its absence in existence, either as a "physical (e.g. brain)" or as a "mental (e.g. existing experience or mind)," in the first place. In the realness of logic, it is not materialism who loses the game, but substance dualism and its"mental" and "physical" substances.

Why can't mental objects be real, or physical? — m-theory

Does '7' exist? You can't point at the symbol, 7, because that is arbitrary, and indeed physical - it can be written as VII, seven, or 7, but always has the same referent, which is a quantity. But only a mind capable of counting can grasp what the symbol refers to. And that is not a physical thing. You can add two apples and two oranges, and get 4 objects. (This is not the same as the problem of universals, but it's related).

Yeah sorry I don't follow here.

There are plenty of examples in nature where abstractions occur.

Golden ratio, fibonacci sequence, and an animal gives birth to a litter of 7.

All these things are real, the only difference I see here is you seem to claim there must be some mind for abstractions to exist, and the realist says these things occur in objective reality without any dependence upon minds.

There are plenty of examples in nature where abstractions occur.

Golden ratio, fibonacci sequence, and an animal gives birth to a litter of 7. — m-theory

The first two are proper constants of nature - nature being ultimately dissipative or growth based processes.

To call them abstractions is misleading as the ratios involved could not be more physically real as limits on rates.

The 7 in a litter is a stochastic process so the number is not special in a universal sense. It is just related to some particular genetic constraint.

There are plenty of examples in nature where abstraction occur. — m-theory

The fact that an animal gives birth to a litter of 7 is not in itself an abstraction. It is an event. It is only when someone comes along and says 'aha, seven pups' that it becomes an abstraction.

All the natural symmetries such as golden ratio, fibonacci sequence, and the like, are attributes of nature that rational reflection has discovered.

Recall the initial discoveries of the relationship between musical harmonies and lengths by the Pythagoreans. Notice how 'ratio' is central to it. So the early rationalists, like the Pythagoreans, explored how 'ratio' of various kinds could be understood by abstraction and measurement. (I just read this morning, how Thales worked out how to measure the height of the pyramid, by working out what time of day his own shadow was his height, and then measuring the shadow cast by the pyramid at that time of day.) This actually was the beginning of rationalism and even 'reason' in the sense that science used to understand it. (Not so much any more, though.)

It was that kind of thinking that became fundamental to the origins of science. It was the abilitiy to count, compare (via ratio), understand laws (logos, logic) that enabled the birth of science. According to the Greeks, only man, 'the rational animal', was capable of this, it set man apart from beast.

The reality of the 'intelligible domain' was central to classical Greek philosophy, and was inherited by the Scholastics, who tended towards realism regarding universals. It was the early nominalists (William of Ockham, Francis Bacon) who challenged and then undermined that understanding and said that 'only particulars exist'. (Conceptualists are like a middle position, saying that numbers (etc) are real but solely as concepts.)

The fact that an animal gives birth to a litter of 7 is not in itself an abstraction. It is an event. It is only when someone comes along and says 'aha, seven pups' that it becomes an abstraction. — Wayfarer

7 is a naturally occurring quantity whether there is some mind to count it or not.

All the natural symmetries such as golden ratio, fibonacci sequence, and the like, are attributes of nature that rational reflection has discovered. — Wayfarer

This is an important point.
The realist claims that we can model nature and reproduce results in nature by exploring rules of formal systems.
The implication is that nature has some set of rules itself, which we can discover, if this is true the realist insists that those laws exist independently and do not necessitate the existence of minds.

It was that kind of thinking that became fundamental to the origins of science. It was the abilitiy to count, compare (via ratio), understand laws (logos, logic) that enabled the birth of science. According to the Greeks, only man, 'the rational animal', was capable of this, it set man apart from beast. — Wayfarer

The rational animal only reproduces natural laws with models, it does not cause them to exist in the first place.

.

The reality of the 'intelligible domain' was central to classical Greek philosophy, and was inherited by the Scholastics, who tended towards realism regarding universals (such as number, ratio, etc.) It was the early nominalists, William of Ockham, Francis Bacon, and others, who challenged that understanding and said that 'only particulars exist'. Conceptualists are like a middle position, saying that numbers (etc) are real but solely as concepts. — Wayfarer

It could be that only particulars exist, and our models only approximate particularism.
But it seems to me there is no way to prove conclusively that this is the case.
Let us ignore that though, even should it be the case that in nature there are only particulars, how does this diminish the practical benefits of universals in the course of human endeavor?

Surely you can't deny that universals are particularly useful?

7 is a naturally occurring quantity whether there is some mind to count it or not. — m-theory

7 is a number, and a number can only be grasped by a mind capable of counting; it is the ability of a rational intelligence to count that is one of its defining qualities.

'What exists anyway' is only a conjecture of naive realism.

The implication is that nature has some set of rules itself, which we can discover, if this is true the realist insists that those laws exist independently and do not necessitate the existence of minds. — m-theory

What kind of realist? I think the idea of 'scientific laws' is actually a bone of contention nowadays. In any case, objective idealists, such as Peirce, believe that such laws are emblematic of the fact that nature seems to have something resembling grammar.

Surely you can't deny that universals are particularly useful? — m-theory

It is nominalism that denies the reality of universals.

7 is a number, and a number can only be grasped by a mind capable of counting; it is the ability of a rational intelligence to count that is one of its defining qualities. — Wayfarer

7 is a real quantity without minds.
Understanding that there is 7 of something requires minds sure, but that there can be 7 things requires no minds.

What kind of realist? I think the idea of 'scientific laws' is actually a bone of contention nowadays. In any case, objective idealists, such as Peirce, believe that such laws are emblematic of the fact that nature seems to have something resembling grammar. — Wayfarer

I think all realist agree that natural laws and reality do not depend upon minds.

It is nominalism that denies the reality of universals. — Wayfarer

It is very real that universals are useful.

How is nominalism useful, what are the practical results of applying nominalism?
Help me understand why I should care that universals are not real.

7 is a real quantity without minds. Understanding that there is 7 of something requires minds sure, but that there can be 7 things requires no minds. — m-theory

The idea that there is a world in which no minds are present, is also a mental construction. You think you can imagine a world with no minds in it, but that is also an act of the imagination. We might imagine what the universe would be like without humans in it. That image might be realistic, but it still depends on a viewpoint or perspective. Without a perspective, what is the scale at which it is seen? Planck scale? Galactic scale? Cosmic scale? What is large, what is small, what is near, what far away? How about duration? An implicit perspective must be introduced to make sense of any kind of universe, even one supposedly without minds. But you're supplying the perspective without realising you're doing it by projecting into the Universe that which is actually in the mind.

This is not just idealist blather, either.

The problem of including the observer in our description of physical reality arises most insistently when it comes to the subject of quantum cosmology - the application of quantum mechanics to the universe as a whole - because, by definition, 'the universe' must include any observers. Andrei Linde has given a deep reason for why observers enter into quantum cosmology in a fundamental way. It has to do with the nature of time. The passage of time is not absolute; it always involves a change of one physical system relative to another, for example, how many times the hands of the clock go around relative to the rotation of the Earth. When it comes to the Universe as a whole, time looses its meaning, for there is nothing else relative to which the universe may be said to change. This 'vanishing' of time for the entire universe becomes very explicit in quantum cosmology, where the time variable simply drops out of the quantum description. It may readily be restored by considering the Universe to be separated into two subsystems: an observer with a clock, and the rest of the Universe. So the observer plays an absolutely crucial role in this respect. Linde expresses it graphically: 'thus we see that without introducing an observer, we have a dead universe, which does not evolve in time', and, 'we are together, the Universe and us. The moment you say the Universe exists without any observers, I cannot make any sense out of that. I cannot imagine a consistent theory of everything that ignores consciousness...in the absence of observers, our universe is dead'.

(Paul Davies, The Goldilocks Enigma: Why is the Universe Just Right for Life, p 271. Linde is one of the originators of 'inflation theory' in the Big Bang.)

How is nominalism useful, what are the practical results of applying nominalism?

Help me understand why I should care that universals are not real. — m-theory

It's as much an historical question as a philosophical one. The debate between (scholastic) realism and nominalism was waged for centuries. In many ways, the nominalists were the precursors to scientific materialism. It's a big subject, I can't summarise the whole topic, but this blog post would be as good a starting point as any.

The idea that there is a world in which no minds are present, is also a mental construction. — Wayfarer

This is circular.

We know the quantity 7 depends on minds, because we have minds therefor the quantity 7 depends on those minds?

That image might be realistic, but it still depends on a viewpoint or perspective. — Wayfarer

This amounts to saying our physical models be might wrong/biased, they might be, but they might also be accurate and unbiased.
If we can't know the right perspective we can't know ours is wrong either.

What I am interested in is how you can be so sure our models are wrong?

An implicit perspective must be introduced to make sense of any kind of universe, even one supposedly without minds. But you're supplying the perspective without realising you're doing it by projecting into the Universe that which is actually in the mind. — Wayfarer

I regard the principle of relativity as dealing with this issue.
Perhaps you have some insight into why it must fail?

This is not just idealist blather, either...
(Paul Davies, The Goldilocks Enigma: Why is the Universe Just Right for Life, p 271) — Wayfarer

Well I am not interested in debating the role of the observer in quantum mechanics.
Suffice it to say there are many interpretations of quantum mechanics and some are less controversial than others when it comes to observer role.
The point being that quantum mechanics does not disprove realism.

It depends on what exactly we mean by "repeatable or recurrent entities." I would say that there are no individuals that can be instantiated or exemplified by many particular things, but there are continua that can be instantiated or exemplified by many particular things. Each such instantiation or exemplification is a different manifestation of the same continuum. — aletheist

Would something like this work as a paraphrase of the general idea: "There are different actual properties, each unique, but where comparatively they are more or less similar, and we form conceptual abstractions where something like 'sphericity' is a range of those comparative similarities. Many not(-yet) actualized, similar-but-unique properties can be actualized that we count as sphericity, where those similarities are ideally in-between, in terms if relative similarities and differences, other actualized examples of the sphericity concept."

you can never be clear that you're comparing like with like, or what the other party means by anything he or she says — Wayfarer

Which is globally the case. It's not as if the world hinges on your beliefs or preferences about this, so that just in case you have a view that meaning is objective and people can share meanings and be clear about that, etc. that doesn't magically avoid that you never be sure that you're comparing like with like or what the other party has in mind re meanings, etc.

I would answer 4? — m-theory

As would I.

How could you be sure you were adding 'like' to 'like'? — Wayfarer

What would that even have to do with me answering 4?

You had just brought up meanings and the issue of whether we can know that we have the same meanings in mind as someone else. What does that have to do with answering "4" to "What's 2 + 2"? Why would I care whether I have the same meanings in mind as you when I answer that? I'd be answering what I think 2 + 2 equals, because that's what you asked me.

As soon as you admit that abstract 'objects' (and as noted, they're not actually objects) are real, it's game over for materialism. — Wayfarer

I don't believe that's necessarily true, although I'd definitely say that in the vast majority of cases, someone isn't going to be both a realist on abstracts and a physicalist. But I'm sure that in the past, either in school or at a conference or something like that--so in person, not online, so that I knew this person had an academic philosophy background, I've run into someone who was a physicalist and who was also a realist on at least some abstracts, so that they believed that abstracts existed physically. I sure can't recall what the details of their view would have been (I can't even recall who it was exactly), and as with the Peircean approach to universalism vs. nominalism, I'm sure it wouldn't have made much sense to me, but at least in the person in question's view, it made sense.

In general, whenever I've thought something like, "If one believes x, then one must believe y," I'm bound to run into someone with a significant philosophical background who defies that--they believe x but not y. So although it can be difficult to avoid thinking things like "If one believes x, then one must believe y," I try to avoid it, because someone will usually come along who falsifies it.

The fact that an animal gives birth to a litter of 7 is not in itself an abstraction. It is an event. It is only when someone comes along and says 'aha, seven pups' that it becomes an abstraction. — Wayfarer

That's correct, and the dog may give birth to numerous litters, so to single out one litter and say she gave birth to seven pups, is something which requires a mind to perform that abstraction.

7 is a real quantity without minds.
Understanding that there is 7 of something requires minds sure, but that there can be 7 things requires no minds. — m-theory

The point being made is that a mind must separate these seven things from the rest of reality, such that there actually is just seven things. You want to say that without a mind, there is those seven things, and that's fine, but there is all the rest of real things as well, and what, other than a mind, separates those seven things from all the rest? So perhaps all the things which exist, exist without a mind, but there are no numbers of things, because they exist as "all the things" and it require a mind to separate out groups, as Wayfarer says, of "like" things. Contrary to what you say then, "that there can be seven things", does require a mind, to individuate those things, and group them as like.

I believe that this principle is more easily understood if you think of reality in terms of events. We may talk about one particular event, such as me writing this "word". But really that particular event is just a part of a larger event which is me writing all these words. And this is part of a large event, my life, which is part of a larger event. We experience all the passing of time as one continuum, and there are no real breaks within the passing of time which allow me to validate writing that word, as a separate event from writing this entire passage, except as an arbitrary choice. This separation of a period of time, to create "an event", is a totally arbitrary division carried out by a mind.

So any time that we individuate an individual object in existence, we arbitrarily separate out a period of time which is proper to that object, allowing for its existence. This is completely arbitrary, and carried out by minds, in order to assume the existence of individual objects. Within a certain arbitrary time period, I am an object with existence. Within a larger period of time, I am just a small part of the existence of a larger object, the human race. Within a larger period of time human beings are part of a larger object, life on earth. Within a larger period of time, the earth is just a part of something else. The point now, is that to validate the existence of individual objects, and therefore "a number of objects", it is necessary to assume a particular time period, and this is an arbitrary thing carried out by minds only.

The point being made is that a mind must separate these seven things from the rest of reality, such that there actually is just seven things — Metaphysician Undercover

How is it that minds cause things to exist as they do, why should there not be 6 when we count at one time, and 8 when we count the next?
If there is no consistency in reality, as this is what you seem to be claiming?

So any time that we individuate an individual object in existence, we arbitrarily separate out a period of time which is proper to that object, allowing for its existence. — Metaphysician Undercover

Except it is not arbitrary, it is necessary to navigate reality.
Why should that be if reality is nothing like the models we form?

Would something like this work as a paraphrase of the general idea: "There are different actual properties, each unique, but where comparatively they are more or less similar, and we form conceptual abstractions where something like 'sphericity' is a range of those comparative similarities. Many not(-yet) actualized, similar-but-unique properties can be actualized that we count as sphericity, where those similarities are ideally in-between, in terms if relative similarities and differences, other actualized examples of the sphericity concept." — Terrapin Station

No, because it still seems to be expressing a version of nominalism, rather than realism. There are different actualizations of a property, each unique but falling within the same inexhaustible continuum of that property's potential manifestations - all of which are real, even those that never have been and never will be actualized.